Carpet tiles

ABSTRACT

An aqueous frothed and filled vinyl chloride and/or vinylidene chloride polymer latex containing an emulsified plasticizer is used to coat and impregnate the back of a carpet. The carpet containing the froth is heated to drive off or evaporate the water and gel the vinyl polymer. While still hot or soft, the froth on the carpet is densified to obtain uniform dimensions or thickness. The resulting laminate is then cooled and cut to the required shape and size for carpet tiles.

This is a divisional application of application Ser. No. 06/615,860filed May 31, 1984 now U.S. Pat. No. 4,595,617.

This invention relates to a method or process for making carpet or floortiles.

An object of this invention is to provide a method or process for makingcarpet tiles and to the product of said method.

These and other objects and advantages of the present invention willbecome more apparent to those skilled in the art from the followingdetailed description, examples and accompanying drawings in which:

FIG. 1 is a vertical schematic view of an arrangement of apparatus whichmay be used in the practice of the process of the present invention and

FIG. 2 is a vertical cross-sectional view of a carpet or floor tileproduced by the process of the present invention.

SUMMARY OF THE INVENTION

According to the present invention, it has been found that a compositionof a latex or emulsion of a vinyl chloride and/or vinylidene chloridepolymer or copolymer, filler and emulsified plasticizer can be frothedand used to coat and impregnate the back of a carpet. After heating todrive off the water and gel or fuse the polymer to plasticize the same,the carpet containing the froth is passed under squeeze or embossingrolls to obtain uniform thickness. After cooling to about roomtemperature, the carpet is cut into suitable shapes useful as carpettiles. An advantage of the present invention is that use can be made ofconventional carpet finishing equipment. Also, the present process ismore economical in that up to 300, or to 500, parts by weight of fillerper 100 parts by weight of vinyl polymer can be used. On the other hand,polyvinyl chloride plastisols can accept only up to about 150 parts byweight of filler per 100 parts by weight of the polyvinyl chloride resinin the plastisol. Also, polyvinyl chloride plastisol compositionsrequire special coating and heating equipment which is eliminated in thepractice of the present invention, and such polyvinyl chloride plastisolcompositions cannot be run on regular carpet equipment.

In FIG. 1 the arrows indicate the direction of movement of the carpet.As shown in FIG. 1, a supply of jute or polypropylene backed tuftedcarpet 1 from carpet supply "J Box" 2 is carried by conveyor 2' overrollers 3, 3 (same number for all of the conveyor rollers) to dip pan 4containing an aqueous precoating or preimpregnating composition which isapplied to the back of the carpet by means of roller coater 4' dippingin the composition. The carpet then is precoated a second time using aprecoating composition in dip pan 5 which is applied by roller coater5'. The precoating compositions can comprise a carboxylatedbutadiene-styrene copolymer latex composition or even a plasticizedvinyl chloride copolymer latex composition used as adhesives to helpsecure the bottom of the carpet tufts to the square woven fabricbacking. The precoated carpet is then passed through preheater 6containing heating elements 6', 6' to dry the carpet. After drying, thecarpet is passed over pretenter 7, 7 and under the froth or foamapplicator and on oven tenter 8 where the frothed filled plasticizercontaining thermoplastic vinyl polymer latex composition is applied tothe back of the carpet by means of supply hose 9 and applicator 10. Thefrothed latex layer 15 on the back of the carpet then passes throughoven 16 where it is dried to remove the water and to fuse or gel thevinyl polymer to make a flexible frothed vinyl polymer. Next, the dryfrothed vinyl polymer composition on the back of the carpet is passedbetween crushing or embossing rollers 17 to emboss or size the frothwhile still soft or warm to get the desired thickness, dimension orfinish for the vinyl polymer composition backed carpet 18. After coolingto room temperature (about 25° C.), the carpet is cut into squares orother shapes to form carpet tiles.

In FIG. 2 there is shown a floor tile of the present inventioncomprising a tufted carpet containing a crushed or embossed filled vinylpolymer composition backing. Exterior tufts or piles 25 are woven attheir bases 26 with square woven jute or polypropylene backing 27 andsecured by adhesive layer 28. The crushed or embossed filled vinylpolymer layer 29 has impregnated and coated the back of the carpet toform the carpet tile.

DISCUSSION OF DETAILS AND PREFERRED EMBODIMENTS

The polymer of the latex comprises a vinyl chloride homopolymer,vinylidene chloride homopolymer, vinyl chloride-vinylidene chloridecopolymers or mixtures thereof. Also, there can be used copolymers of atleast 50% by weight of at least one monomer selected from the groupconsisting of vinyl chloride and vinylidene chloride and the balanceessentially at least one other copolymerizable or copolymerizedmonoethylenically unsaturated monomer, other than said vinyl chlorideand said vinylidene chloride monomers, having from 2 to 14 carbon atomsand mixtures of such copolymers. Such other copolymerizable monomers arethe nitriles like acrylonitrile and methacrylonitrile; the acids likeacrylic, methacrylic, itaconic, maleic and fumaric acids and theiresters like methyl acrylate, ethyl acrylate, butyl acrylate, octylacrylate, methyl methacrylate, n-butyl methacrylate, n-octylmethacrylate, diethyl maleate and diethylfumarate; olefins likeethylene, propylene and isobutylene; maleic anhydride; vinyl acetate;vinyl benzoate and butyl vinyl ether and the like and mixture of thesame. These copolymers, also, may be made by graft oroverpolymerization. Mixtures of homo and copolymer latices can be used.Some examples of the vinyl chloride and/or vinylidene chloridecontaining copolymers are vinyl chloride-acrylonitrile copolymer, vinylchloride-diethylmaleate copolymer, vinyl chloride-diethyl fumaratecopolymer, vinyl chloride-maleic anhydride copolymer, vinylchloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer,vinyl chloride-vinyl acetate-maleic anhydride copolymer, vinylchloride-isobutylene copolymer, vinyl chloride-vinyl isobutyl ethercopolymer, vinyl chloride-acrylic acid copolymer, vinylchloride-methacrylic acid copolymer, vinyl chloride-itaconic acidcopolymer, vinyl chloride-methyl acrylate copolymer, vinylchloride-ethyl acrylate copolymer, vinyl chloride-butyl acrylatecopolymer, vinyl chloride-octyl acrylate copolymer, vinylchloride-methyl methacrylate copolymer, vinyl chloride-vinyl benzoatecopolymer, vinyl chloride-butyl acrylate-acrylic acid copolymer,vinylidene chloride-acrylonitrile copolymer, vinylidenechloride-methacrylonitrile copolymer, vinylidene chloride-methylacrylate copolymer, vinylidene chloride-butyl acrylate copolymer,vinylidene chloride-diethyl fumarate copolymer, vinylidenechloride-butyl vinyl ether copolymer, vinylidene chloride-fumaric acidcopolymer, vinylidene chloride-maleic acid copolymer, vinylchloride-vinylidene chloride-2-ethyl hexyl acrylate copolymer,vinylidene chloride-vinyl chloride-acrylonitrile copolymer and the likeand mixtures thereof. Vinyl chloride copolymers containing --COOHmoities from acrylic acid and the like are preferred.

One or more surfactants are used during emulsion polymerization to formthe latices. Mixtures of surfactants can be used. Surfactants includeconventional surfactants, emulsifiers, soaps, micelle formers,stabilizers and so forth which are compatible with the monomers andcatalysts used during the aqueous free radical emulsion polymerization.Examples of some surfactants which may be used are sodium dodecyldiphenyl oxide disulfonate, sodium lauryl sulfate, sodium dodecylsulfate, sodium decyl diphenyl oxide disulfonate, sodium dodecylsulfonate, sodium dodecyl benzene sulfonate, bis(1-methylamyl) sodiumsulfosuccinate, diamyl sodium sulfosuccinate, diisobutyl sodiumsulfosuccinate, dihexyl sodium sulfosuccinate, di-tridecyl sodiumsulfosuccinate, sodium rosinate, dioctyl sodium sulfosuccinate,potassium stearate, potassium soap of disproportionated wood rosin,potassium laurate, potassium soap of disproportionated tall oil rosin,sodium soap of stabilized resin, N-octadecyl sulfosuccinamate, ammoniumstearate and the like.

Polymerization of the monomers is effected by free-radical catalysts(free-radical formers or free-radical forming systems) or initiatorssuch as ammonium, potassium and/or sodium persulfate, H₂ O₂ and the likein an amount sufficient for polymerization of the monomers and to obtainthe desired molecular weight. Other free-radical catalysts can be usedwhich decompose or become active at the temperature used duringpolymerization. Examples of other free-radical catalysts are cumenehydroperoxide, dibenzoyl peroxide, diacetyl peroxide, didecanoylperoxide, di-t-butyl peroxide, dilauroyl peroxide, bis(p-methoxybenzoyl) peroxide, t-butyl peroxy pivalate, dicumyl peroxide, isopropylpercarbonate, di-sec-butyl peroxydicarbonate,azobisdimethylvaleronitrile, 2,2'-azobisisobutyronitrile,2,2'-azobis-2-methylbutyronitrile and 2,2'-azobis (methylisobutyrate)and the like and mixtures of the same. Redox systems, also, can be used.Only minor amounts of catalyst are necessary to effect polymerization.

Temperatures used during emulsion polymerization should be sufficient toeffect polymerization by activation of the catalyst and double bonds ofthe monomer(s). They should not be too high to cause a run-away reactionand not too low to retard polymerization. In general, the temperaturemay be from about 50° to 80° C. Times for polymerization may vary fromabout 5 to 14 hours depending on the degree of polymerization desired.Generally, it is desired to carry polymerization to 100% conversion.

The water used during emulsion polymerization should be free ofdeleterious materials and preferably should be distilled or ionexchanged. Sufficient water is used to enable formation of the emulsionand to enable proper mixing or stirring of the ingredients duringpolymerization to obtain the desired rate and degree of polymerization,heat transfer and so forth. The solids content (after removal of water),thus, may vary from about 10 to 60% by weight, preferably from about 30to 55% by weight.

Polymerization preferably should be conducted in a closed reactor, suchas a pressure reactor, fitted with a stirrer or other agitating means,heating and cooling means, with means to flush with or pump in an inertgas such as nitrogen, helium, argon, neon and the like in order topolymerize preferably under inert or non-reactive conditions, with meansto charge monomer, water, catalysts and so forth, venting means, andwith means to recover the polymer and so forth. The reactor should becleaned or flushed out between polymerization runs to remove traces ofshortstops, catalysts, modifier, residues and so forth which mightinterfere with subsequent polymerizations. There should be sufficientagitation or stirring of the polymerization media to ensure thoroughmixing, diffusion, contact and so forth.

Modifiers, chelating agents, reducing agents, buffers and the like maybe used during polymerization. Also, short stops may be added to stopthe polymerization. After polymerization there may be added to the latexstabilizers, antioxidants, biocides, antidegradants, preservatives andthe like.

Free radical aqueous emulsion polymerization and copolymerization,including graft or overpolymerization, to form latices of ethylenicallyunsaturated monomers is well known to those skilled in the art. Sincesome monomers may polymerize faster than others, some blocks may form inthe copolymers. Blocks may be reduced or eliminated by proportioning orother means as disclosed in the prior art. In this connection please seeBovey et al, "Emulsion Polymerization," High Polymers, Vol. IX,Interscience Publishers, Inc., 1955; Schildknecht, "Vinyl and RelatedPolymers," John Wiley & Sons, Inc., New York, 1952; "Encyclopedia ofPolymer Science and Technology," Vol. 5 (1966), Vol. 8 (1968), Vol. 10(1969) and Vol. 14 (1971), Interscience Publishers, a division of JohnWiley & Sons, Inc., New York; Ham, "Copolymerization," High Polymers,Vol. XVIII, Interscience Publishers a division of John Wiley & Sons, NewYork, 1964; Burlant and Hoffman, "Block and Graft Polymers," ReinholdPublishing Corporation, New York, 1960; Ceresa, "Block and GraftCopolymers," Butterworth & Co. (Publishers) Ltd., London, 1962; Ceresa,"Block and Graft Copolymerization," Vol. 1 (1973) and Vol. 2 (1976),John Wiley & Sons, Ltd., New York; Battaerd and Tregear, "GraftCopolymers," Polymer Reviews, Vol. 16, Interscience Publishers, adivision of John Wiley & Sons, New York, 1967 and "Modern PlasticsEncyclopedia," Vol. 57, No. 1OA, 1980-81, October 1980, McGraw-Hill,Inc., New York. The graft copolymer may contain all graft copolymer butalso may be a mixture of homopolymers, copolymers as well as the graftitself, depending on the rate of polymerization of the monomers underthe polymerization conditions and so forth.

To make the carpet backing composition the vinyl polymer latices aremixed with one or more emulsified compatible plasticizers, fillers and afrothing agent.

Examples of suitable or compatible plasticizers for the abovethermoplastic vinyl polymers are the adipates like dibutyl adipate,di-(2-ethyl hexyl) adipate, dicapryl adipate, polyester adipates and soforth; the azealates like di-(2-ethyl hexyl) azealate, dibutoxyethylazealate and so forth; the benzoates like diethylene glycol dibenzoate,dipropylene glycol dibenzoate; the epoxy derivatives like epoxidized soybean oil; the glutarates like diisodecyl glutarate, polyester glutaratesand so forth; the chlorinated paraffins; the phosphates liketri-(2-ethyl hexyl) phosphate, tri cresyl phosphate and so forth; thephthalates like dibutyl phthalate, diisononyl phthalate, dioctylphthalate (preferred), di-(2-ethyl hexyl) phthalate, diisodecylphthalate, didecyl phthalate and so forth; polymeric polyesters; thesebacates like dibutyl sebacate, dioctyl sebacate and so forth and thelike and mixtures thereof. The plasticizers are mixed in a suitablemixing machine with water and a surfactant similar to that used duringpolymerization to emulsify the plasticizer. The water is used in anamount sufficient to provide a solids content of the plasticizer of fromabout 60 to 80% by weight. In general, the plasticizer (dry) is used inan amount required to get the desired flexibility, lowered Tg orsoftness on gelling or fusing of the vinyl polymer. Preferably, theplasticizer is used on a dry weight basis in an amount of from about 15to 75, more preferably from about 40 to 60, parts by weight per 100parts by weight total (dry) of the vinyl polymer(s). Some commerciallyavailable vinyl chloride type latices are already preplasticized, but itmay be desirable or necessary to add more emulsified plasticizer.

Inorganic fillers are added to the latex in an amount of from about 100to 500, preferably from about 200 to 400, parts by weight per 100 partsby weight (dry) of the vinyl polymers. Examples of useful fillers arecalcium carbonate (preferred), barytes, aluminum trihydrate, clay andthe like and mixtures thereof. The fillers should be finely divided.

A frothing agent is used in a minor amount by weight (dry) sufficient tofroth the vinyl polymer composition. Preferably, it is used in an amountof from about 2 to 7 phr (dry basis) to form a froth or foam of thelatex, emulsified plasticizer and filler. Frothing agents to form foamsare well known. A suitable frothing agent comprises urea, the sodiumsalt of condensed naphthalene sulfonic acid, mixed C₈ -C₁₈ fattyalcohols, ammonium or sodium lauryl sulfate and water. See U.S. Pat. No.4,172,067. The frothing or whipping of the latex mixture or compositioncan be conducted in an Oakes, Firestone or other type foamer using airor an inert gas like nitrogen to the desired froth density. Mixtures offrothing agents can be used.

When frothed, these backing compositions can give compound frotheddensity ranges of from about 500 to 1500 grams per quart using theOakes, Firestone or other type carpet industry foamer after adjustmentof the foamer.

In some instances it is not necessary to pass air or inert gas throughthe Oakes or other foamer to mix with the backing composition to froththe composition. Rather, reliance can be had on the air or gas alreadyabsorbed by the ingredients of the backing composition on theirproduction, exposure to the atmosphere, handling, mixing together and soforth to obtain the desired froth density.

Other compounding ingredients may be added to the vinyl polymer latexcomposition or compound such as thickeners, pigment colors, additionalsurfactants, defoamers for use during blending and so forth.

The compounded aqueous frothed vinyl polymer coating composition can beapplied to the back of the carpet by air knife coating, blade coating,brush-finish coating, cast coating, flow-on coating, knife coating,machine coating, polished drum coating, print on coating, roll coating,spray coating, wire wound rod coating or other methods known to the artfor coating the backing of a carpet. The frothed vinyl composition isapplied to the back of the carpet to saturate the bottoms of the tuftsand backing in an amount of from about 25 to 30% by weight of thecarpet.

The carpet containing the frothed or cellular vinyl polymer compositionis then passed through an oven at 270° to 350° F. to remove the waterand to fuse or gel the vinyl polymer to form a cellular or frothedplasticized filled thermoplastic vinyl polymer composition layer on theback of the carpet. While the thermoplastic layer is still soft or hot,the carpet is compressed by passing through embossing or squeeze rollsto obtain a uniform thickness of from about 1/16" to 3/32". Aftercooling to ambient room temperature, the vinyl coated carpet is cut intosquare shapes or tiles of about 12"×12" or 18"×18". However, the tilesmay be cut in other shapes.

The composition of the present invention can be applied to the back ofany woven or nonwoven carpet (or rug) material to aid in securing thebase yarns of the carpet such as Wilton, Axminster, knitted and othercarpets, as well as to a secondary backing, it is particularly useful inthe manufacture of piled or tufted carpet tiles. In piled or tuftedcarpets the fibers or yarn is needled or looped through the intersticesor holes in a square woven or nonwoven primary cloth such as cotton,polypropylene, jute or other natural or synthetic fibrous material ormixture thereof. For a discussion of the manufacture of carpets andespecially tufted carpets please see "Carpets And Other Textile FloorCoverings," Robinson, 2nd Ed., 1972, Textile Book Service, Division ofBonn Industries Inc., The Trinity Press, London. Please, also, see"Wellington Sears Handbook of Industrial Textiles," Kaswell, 1963,Wellington Sears Co., Inc., New York.

The yarns or tufts of the carpet can be natural or synthetic organicfibers or mixture thereof. Additionally, the yarns may vary from onetype to another type. Examples of such yarns are those from silk,cotton, wool, hair, nylon, acrylics ("Acrilan"), polyester, polyvinylchloride, vinyl chloride-vinyl acetate copolymers, polyurethanes, rayon,polyacrylonitriles, vinyl chloride or vinylidene chloride copolymerizedwith acrylonitrile, polyvinylidene chloride, polypropylene fibers andthe like. Glass fibers may be blended or woven with the natural and/orsynthetic organic fibers. These fibers or yarns can contain fireretardants, antistatic agents, bacteriostats, antidegradants, dyes,pigments, optical brighteners and so forth.

The following examples of backing compositions for making carpet tileswill serve to illustrate the present invention with more particularityto those skilled in the art. In the examples, the parts are parts byweight unless otherwise indicated. A minor or very small amount byweight of an aqueous alkali swellable polyacrylate thickener was addedto each backing composition to give each composition an unfrothedBrookfield (RVF model) viscosity of from about 12,500 to 13,500 cps (#4spindle at 20 rpm).

EXAMPLE 1

The following ingredients were mixed together to form an aqueousdispersion of latex and compounding ingredients suitable as a carpetbacking to form carpet tiles:

    ______________________________________                                                          Parts By Weight                                             Ingredient          Dry     Wet                                               ______________________________________                                        Latex (aqueous emulsion).sup.(1)                                                                  100.00  183.40                                            Non-silicone surface orienting                                                                    .50     .50                                               type defoamer                                                                 N--octadecyl sulfosuccinamate                                                                     1.50    5.00                                              (anionic surfactant)                                                          Calcium carbonate   300.00  300.00                                            Inorganic pigment (color)                                                                         .35     .35                                               Froth aid.sup.(2)   4.50    18.00                                             Di-octyl phthalate aqueous                                                                        50.00   71.45                                             emulsion (70% TSC)                                                            ______________________________________                                         .sup.(1) Blend of three latices of:                                           (a) 37.5% by weight (dry) of a copolymer of about 89% by weight of vinyl      chloride, 10% butyl acrylate and 1% acrylic acid, about 35% solids;           (b) 37.5% by weight (dry) of a copolymer of about 90% by weight of vinyl      chloride and 10% ethyl acrylate and                                           (c) 25% by weight (dry) of an ethylenevinyl chloride copolymer containing     about 64% copolymerized vinyl chloride, about 33% solids.                     .sup.(2) Composition comprising urea, sodium salt of condensed naphthalen     sulfonic acid, mixture of C.sub.8 to C.sub.18 fatty alcohols, ammonium or     sodium lauryl sulfate and water. See U.S. Pat. No. 4,172,067.            

Application of froth on the back of a carpet was about 100 oz. persquare yard. The froth on the carpet was then heated to remove water andgel the polymers. The carpet was passed through rollers while thepolymers were hot to get the desired density, cooled and cut into carpettiles.

EXAMPLE 2

This example is similar to Example 1, above. The following ingredientswere mixed together to form a composition suitable for making carpettiles:

    ______________________________________                                                             Parts By Weight                                          Ingredient             Dry     Wet                                            ______________________________________                                        Latex (copolymer of about 89% by                                                                     100.00  183.40                                         weight of vinyl chloride, 10% butyl                                           acrylate and 1% acrylic acid)                                                 Non silicone surface orienting type                                                                  .50     .50                                            defoamer                                                                      N--octadecyl sulfosuccinimate                                                                        1.50    5.00                                           Calcium carbonate      300.00  300.00                                         Inorganic pigment (color)                                                                            .35     .35                                            Froth aid.sup.(2)      4.50    18.00                                          Dioctyl phthalate aqueous                                                                            50.00   71.45                                          emulsion (70% TSC)                                                            ______________________________________                                         .sup.(2) Same as in Example 1.                                           

The above composition was whipped with air to make a froth which wasapplied to the back of a carpet, heated to fuse and dry, crushed andused to make carpet floor tile.

EXAMPLE 3

This example is similar to Example 1, above. The following ingredientswere mixed together to form a composition suitable for making carpettiles:

    ______________________________________                                                            Parts By Weight                                           Ingredient            Dry     Wet                                             ______________________________________                                        Latex (copolymer of about 87% by                                                                    50.00   91.60                                           weight of vinyl chloride, 10% butyl                                           acrylate and 1% acrylic acid)                                                 Latex (copolymer of about 36% by weight                                                             50.00   100.00                                          of ethylene and 64% of vinyl chloride)                                        Non silicone surface orienting type                                                                 .50     .50                                             defoamer                                                                      N--octadecyl sulfosuccinamate                                                                       1.50    5.00                                            Calcium carbonate     300.00  300.00                                          Inorganic pigment (color)                                                                           .35     .35                                             Froth aid.sup.(2)     4.50    18.00                                           Dioctyl phthalate aqueous emulsion                                                                  50.00   71.45                                           (70% TSC)                                                                     ______________________________________                                         .sup.(2) Same as Example 1.                                              

The above composition was whipped with air in a frothing machine to makea froth which was applied to the back of a carpet, heated to fuse anddry the froth, crushed and used to make floor tiles.

I claim:
 1. An aqueous composition comprisinga. a latex of a vinylpolymer selected from the group consisting of polyvinyl chloride,polyvinylidene chloride, copolymers of vinyl chloride and vinylidenechloride and copolymers of at least 50% by weight of at least onemonomer selected from the group consisting of vinyl chloride andvinylidene chloride and the balance essentially at least onecopolymerizable ethylenically unsaturated monomer, other than said vinylchloride or vinylidene chloride, having from 2 to 14 carbon atoms andmixtures of said polymers, b. an aqueous emulsified compatibleplasticizer for said vinyl polymer in an amount (dry) sufficient toplasticize said vinyl polymer to achieve flexibility on fusing, c. fromabout 100 to 500 parts by weight of finely divided inorganic filler per100 parts by weight (dry) of said vinyl polymer and d. a frothing agentin an amount by weight (dry) sufficient to froth said composition.
 2. Anaqueous composition according to claim 1 where said plasticizer is usedin an amount of from about 15 to 75, preferably from about 40 to 60,parts by weight total (dry) per 100 parts by weight (dry) of said vinylpolymer and where said filler is used in amount of from about 200 to 400parts by weight per 100 parts by weight (dry) of said vinyl polymer. 3.An aqueous composition according to claim 1 where said filler is calciumcarbonate.
 4. An aqueous composition according to claim 3 where saidlatex is a blend ofa vinyl chloride-butyl acrylate-acrylic acidcopolymer latex, a vinyl chloride-ethyl acrylate copolymer latex and anethylene-vinyl chloride copolymer latex.
 5. An aqueous compositionaccording to claim 3 where said latex is a vinyl chloride-butylacrylate-acrylic acid copolymer latex.
 6. An aqueous compositionaccording to claim 3 where said latex is a blend ofa vinylchloride-butyl acrylate-acrylic acid copolymer latex and anethylene-vinyl chloride copolymer latex.